A motor control system for a lubricant pump motor comprises a pump system power input, a motor drive, a current sensor, a lubrication controller, and a drive controller. The pump system power input is configured to supply system power. The motor drive is configured to drive the lubricant pump motor using the system power. The current sensor is disposed between the pump system power input and the motor drive to sense an input current of the system power. The lubrication controller configured to provide motor activation signals. The drive controller is disposed to receive the motor activation signals via an isolated digital input, and to control the motor drive as a function of the sensed input current and a user-defined current set-point, in response to the activation signals.